Experts in the struggle against broomrape

Evrosem is an expert in the struggle against sunflower broomrape

The problem of the Sunflower broomrape or Orobanche cumana, despite the constant combat with it, has an international scale. The parasite Sunflower broomrape is confidently spreading throughout the world including Ukraine. It is estimated that about 16 million hectares of sunflower crops are affected by broomrape each year. The Institute of Field and Vegetable Crops NS Seme deals with the reproduction and distribution features of the Sunflower broomrape plant in Europe. Evrosem is the only official partner of the Institute of Field and Vegetable Crops in Ukraine to study the parasitic plant and ways to control it.

 

On 20th September, 2018, Evrosem and NS Seme signed a memorandum of cooperation in the field of researching new broomrape races and testing new sunflower hybrids in local parasite races.

 

A separate scientific division Pole Znan (Field of Knowledge) of Evrosem company conducts research in the following areas:

  • Study of geographic and racial identification and diversity of broomrape population in Ukraine;
  • Identification of species and populations of plants with the genus Helianthus, which are donors of resistance genes to local broomrape races, on 5 testing sites each containing 300 resistance donors;
  • Testing of methods and ways of broomrape seed distribution;
  • Search for methods to combat and curb the parasite spread on the territory of Ukraine;
  • Laboratory and greenhouse research conducted by Pole Znan specialists, study of germination stimulants and resistance markers.

Many countries around the world grow strategically important crops, such as sunflowers. But its crops as well as tobacco, clover, hemp and tomato crops are often affected by broomrape. This parasitic plant has a pale brownish stem color and scaly leaves, which due to the lack of chlorophyll are never green. It has numerous flowers at the top of the stem. Its lower part expands and attaches to the roots of host plants. One plant can produce up to 500 thousand small seeds, which are easily transported by wind and agricultural machinery. It is extremely difficult to fight it.

HARMFUL EFFECTS

  • WHEN AFFECTED BY BROOMRAPE, THE ROOTS AND AERIAL PARTS OF THE SUNFLOWER PLANTS LACK IN WATER AND NUTRITION
  • LOSS OF WATER LEADS TO IMPAIRED TRANSPIRATION OF THE AFFECTED PLANT, WATER DEFICIT INCREASES SEVERAL TIMES AND PHOTOSYNTHETIC ACTIVITY DECREASES
  • WHEN SUNFLOWER PLANTS ARE AFFECTED, THEIR GROWTH AND DEVELOPMENT SLOWS DOWN, WHICH IN ITS TURN LEADS TO SIGNIFICANT CROP LOSSES
  • SUNFLOWER LEAVES WITHER AND DROOP DUE TO WATER SHORTAGE, AFTER A WHILE THEY TURN YELLOW

Parasite lifecycle

  • Broomrape is a herbaceous chlorophyll-free plant in the family of Orobanchaceae. There are annual and perennial biological life forms.
  • The broomrape roots (haustoria) look like short fleshy fibers.
  • Stems grow to an average of 50-80 cm.
  • The flowers, fused in pairs in the form of panicles, are pollinated by insects. Self-pollination is possible.
  • The fruit is a multi-seeded capsule.
  • Brownish seeds have a rounded or oblong shape and remain viable for up to 20 years.

Parasite reproduction cycle

The broomrape reproduces by seeds, which germinate on the soil surface at a temperature of about + 20 ° C, as soon as provocative plants appear (corn, flax, lettuce, beets, etc.), and looks like a filamentous seedling. If a host plant is encountered on its growth way, the seedling immediately sucks into it to extract nutrients from it. Due to this, it begins to thicken.

Soon the parasite stem emerges from the thickening where the flowers start blooming. The broomrape plant absorbs water and mineral components and releases metabolic products into the host’s root system. As for the sunflower, it begins to lag far behind in development and growth, its yield is sharply reduced. Up to 200 parasite shoots can settle on one sunflower root. The broomrape negative effect leads to the death of the plant on which it settles.

Рlant disease symptoms

1. The leaves of a cultivated plant begin to lose turgor, turn yellow and droop.

2. Whitish-yellow shoots of the broomrape are observed on the roots.

Broomrape evolution

More than 120 species of broomrape are known. It is distributed all over the world, parasitizing both cultivated and wild plants. Farmers in those countries that process sunflower are especially affected by it. The constant variability of the broomrape through cross-pollination leads to the emergence of new races that are resistant to the developed prevention and control measures.

The parasite was first mentioned at the end of the XIX century under the definition of the race A. In a quarter of a century the race B was discovered, then in 1960 the race C appeared, and in 1990 two races D and E were discovered at once. But the most aggressive were the races G and H, found in countries such as Romania, Turkey and Spain.

New races of the parasite appear every year, so plant breeders have to breed genetically resistant varieties of sunflower every year. Attached to the root of a genetically resistant hybrid, the broomrape loses the ability to form a bud and stops its development.

Basic methods of weed control

– Increasing the tillage depth (more than 20 cm).

– Competent crop rotation with 8-9-year cycle of sunflower return to the cultivation place.

– The use of hybrid varieties resistant to the harmful effects of the parasite.